The objective of this research is to investigate the loss of normal responsiveness of embryonic chick cells to glucocorticoids following viral transformation and to compare this in chemically transformed cells. A model will be developed that has normal and transformed glucocorticoid-responsive cells and transformed unresponsive cells. Normal chick embryo cells and wild-type and T5 mutant Rous sarcoma virus infected chick cells will be used to develop this model. The T5 mutant-transformed cell exhibits the normal phenotype at 41 degrees C, but it becomes transformed when the temperature is lowered to 35 degrees C. This infected cell can become unresponsive to the glucocorticoids within a few hours. The effects of variation in the phases of the cell cycle and enucleation of cells on glucocorticoid responsiveness also will be investigated. The structural and functional specificity of glucocorticoids will be correlated in normal and transformed cells. In all studies, glucocorticoid binding will be correlated with inhibitory effects on glucose and thymidine uptakes.